1. Field of Invention
This invention pertains to an extension valve for an impact dispersal system. More particularly, this invention pertains to an extension valve that is actuated by a pressurized fluid, such as from a brake system, and allows a pressurized fluid to flow to a cylinder, thereby causing the cylinder piston to extend to an impact ready position.
2. Description of the Related Art
In today's fast paced society, there are sudden stops and unexpected impacts. When these sudden stops and impacts involve vehicles or other massive objects, injury and/or equipment damage is likely. Various attempts have been made to minimize the damage due to such impacts.
For example, U.S. Pat. No. 3,677,595, titled “Automobile Bumper,” issued on Jul. 18, 1972, discloses a bumper that is hydraulically extended by actuation of an electric switch connected to the brake pedal of a vehicle. The switch connects the power steering system to hydraulic cylinders that extend the bumper away from the vehicle. Upon an impact of the extended bumper, the pressure in the hydraulic cylinders is relieved by a pressure relief valve that allows the hydraulic fluid to return to the power steering system.
U.S. Pat. No. 3,947,061, titled “Extensible vehicle bumper,” issued on Mar. 30, 1976, discloses a motor vehicle bumper that is operated by hydraulic slave cylinders connected to the master brake cylinder to extend the bumper upon the application of a predetermined amount of force to the brake to provide the bumper with a greater shock absorbing length of travel under collision conditions. A spring forces the extended bumper to return to a non-extended position. Upon impact, the hydraulic pressure is relieved through a valve returning the hydraulic fluid to the brake system.
U.S. Pat. No. 5,096,242, titled “Shock-absorbing bumper system,” issued on Mar. 17, 1992, discloses a brake-actuated shock-absorbing bumper system for an automotive vehicle. The shock-absorbing bumper system includes a supply subsystem 1 for supplying pressurized working fluid, a pressure-balancing subsystem 2, a switching subsystem 3, front and rear bumper subsystems 4 and 4′, a feedback subsystem 5, a safety-control subsystem 6, and a conduit system having a plurality of oil paths for connecting subsystems 1, 2, 3, 4, 4′, 5, and 6. In one embodiment, illustrated in FIGS. 6 and 6A, the bumper 41, after being subject to an impact, has a working fluid within a second chamber 45 that absorbs a portion of the impact, a spring 47 that absorbs a portion of the impact, and a receiving space 481 that receives the cylinder 40 after a shear pin 43 breaks. U.S. Pat. No. 6,312,027, titled: Shock absorbing system for an automotive vehicle,” issued on Nov. 6, 2001, is a later-issued patent by the same inventor that discloses a shock absorbing system for an automotive vehicle with additional features.
U.S. Pat. No. 5,286,138, titled “Vehicle positioning methods and apparatus with impact damper,” issued on Feb. 15, 1994, discloses a pair of hydraulic cylinders 68, 69 having a check valve 108 in parallel with a needle valve 109 connected to the hydraulic cylinder 68, 69. The check valve 108 allows for filling the hydraulic cylinder 68, 69 without subsequent escape of the fluid, and the needle valve 109 allows hydraulic fluid to bleed from the cylinder 68, 69, which results in a slow retraction of the pistons 72, 73.
U.S. Pat. No. 5,370,429, titled “Bumper system having an extendable bumper for automotive vehicles,” issued on Dec. 6, 1994, discloses a hydraulic cylinder connected to a vehicle bumper, with the bumper being extended from the vehicle in response to conditions indicative of an imminent accident. In one embodiment, the cylinder includes a groove with a decreasing opening corresponding to the amount of retraction of the cylinder. The groove with the variable sized opening changes the impact resistance based on the amount of extension of the bumper.
U.S. Pat. No. 6,435,578, titled “Energy dissipating device for an automobile bumper,” issued on Aug. 20, 2002, discloses a hollow rod piston 2, 10 that selectively closes damping holes 6, 14 as the hydraulic cylinder, or energy dissipater, 3, 11 dissipates the energy from an impact.